11 cards where the illustration contains “oil-painting-medium”

Assassin (War of the Spark Tokens #6)
Faithless Looting (Strixhaven Mystical Archive #38)
Harmonize (Strixhaven Mystical Archive #52)
Kunoros, Hound of Athreos (Theros Beyond Death #341)
Mox Diamond (From the Vault: Relics #10)
Nylea's Intervention (Theros Beyond Death #188)
The Eternal Wanderer (Phyrexia: All Will Be One #11)
Tuskguard Captain (Khans of Tarkir #156)
Tymaret, the Murder King (Theros #207)
Void Beckoner (Ikoria: Lair of Behemoths #373)
Wardscale Crocodile (War of the Spark #183)

The message was clear to Sorin—time to search for something else.